A Biological Basis for the 8-Hour Workday? Researchers uncover 8- and 12-hour Cycles of Gene Activity
http://www.physorg.com/news159642057.html

Note
Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by PhysOrg.com in any form.